Stale fuel disposal

[bookwa]

I need to dispose of around 80 litres of petrol that is two years old.  Will siphon it out of the underfloor tank and then what?Any ideas on how to dispose of it would be appreciated

cheers

[zmk1962]

Lots of prior discussion on this if you search the forums. 
What type of motor are you running- 2stroke carbie model or newer 4stroke or direct injection model?
Also you have 80L but how big is your tank? 

I run a 200hp EFI 2stroke.  If it was mine I’d mix 50:50 with fresh premium unleaded 98RON, whack on a new water separating fuel filter and use it. 

You typically need 91RON for an outboard. The fresh 98 would raise your octane and the filter will get rid of the gunk. 
 

Cheers Zoran 

[bookwa]

Thanks Zoran.  Yammie 70 four stroke.  Buggerall hours. Bought it then decided to have a triple bypass.  Hence the situation

Tank is 80 capacity and there’s probably 70 in there

ive been running on a portable tank but want to go back to using the main tank and have the little one for backup.  

Cheers

[Rebel]

Hi,

The local Council will advise you.

Cheers

[kingie chaser]

What makes you think the fuel is stale?

Just because of its age?

Id run it on land to see how it performs, maybe put a measured amount of a fuel treatment like Fuel Doctor before you do this!

https://fueldoctors.com.au/product/

Also your tank being 90% full would have been better on the fuel than if there was 10ltrs so I be inclined to use it rather than just ditching it. 

 

But yes local councils either have depots or do a service at different times of the year.

I have taken paints, used batteries, oils, chemicals, expired gas bottles etc to the local council depot without issue but it depends on your council!

 

 

Edited December 31, 2019 by kingie chaser

[zmk1962]

47 minutes ago, bookwa said:

Thanks Zoran.  Yammie 70 four stroke.  Buggerall hours. Bought it then decided to have a triple bypass.  Hence the situation

Tank is 80 capacity and there’s probably 70 in there

ive been running on a portable tank but want to go back to using the main tank and have the little one for backup.  

Cheers

Oh dear... hope you are all ok now !  

I forgot to ask one qualifying question, is the fuel in the tank E10 ?  If so get rid of it.  The ethanol would definitely have separated and oxidised to acetic acid.

If its just unleaded, then given there's 70L in an 80L tank and the boat is probably stored tilted back, you most likely don't have a lot of fuel surface exposed to air (so not much loss of octane due to volatile evaporation). If your breather tube had a bit of fuel in there then this fuel would have acted as a plug, moving with the vapour expansion and effectively sealing the tank. 

I'd still do as I recommended initially. Siphon out 20-40L (2 x 20L Jerry cans or your portable tank if its near empty).  Top up the main tank  with 98.  I'd change the fuel filter as it will remove any water condensate that may have occurred.  

I often have 80-100L lying around in my 250L tank for months and that's what I have done for 20+yrs with no issues.

You can progressively mix in the 20-40L that you have siphoned out (keep topping up with 98 or 95).  Or like me, if I have siphoned out fuel, I have topped up the daughters Micra, and Hyundai, the wife's Subaru,  or the Landcruiser, lanmower, whipper snipper etc. It gets used up and mixed with fresh fuel a lot quicker in cars.

Cheers Zoran

[bookwa]

Thanks everyone for the advice.  Zoran I’ll follow your suggestions and see how we go

cheers

[Yowie]

I was advised by an experienced outboard mechanic/champion speed boat driver to NEVER use ethanol based petrol in any outboard motors, only use straight petrol, and preferably 95RON - (of course add oil for a 2 stroke)

The ethanol will attack and damage certain engine components, more so than in vehicle engines for which it is designed.